The present invention relates to a file management device and a method thereof, and an audio visual data recording/reproducing device and a method thereof Particularly, the present invention relates to a file management device and a method thereof, and an audio visual data recording/reproducing device and a method thereof for easily managing files.
For example, a news program broadcast in a broadcasting station presents a scene which provides brief cuts continuously. If AV data as desired material data are recorded at separate positions of one video tape which is used for editing such a news program or the like, it takes a time to place an edit point to the head. Besides, when material data recorded on a plurality of video tapes are edited, it is necessary to exchange the video tapes, making editing works inefficient.
In recent years, a broadcasting station or the like extensively uses a video server (AV server) which records AV (Audio Visual) data such as moving pictures or sound on a randomly accessible recording medium such as an HD (Hard Disk) and allows for editing or broadcasting by using the AV data.
The video server includes a large capacity recording device composed of a plurality of HDs called RAID (Redundant Arrays of Inexpensive Disks), and accordingly, since all of material data to be edited can be recorded in the RAID and the RAID is randomly accessible, there is no such a problem that it takes a time to put an edit point to the head or it is necessary to exchange recording media, as described above.
By the way, the video server handles the material data to be edited or edited AV data in units of files. There may be a need for creating a scene of contiguous short cuts as a file on a conventional video server, for example. In such a case, it has been a common practice to ensure a new recording region in the video server (RAID which the video server includes), and copy necessary material data to be edited in the record region like a dubbing operation of a video tape.
However, the material data is recorded in the video server. Re-copying or re-recording this data as an edit result on the video server is redundant and wasteful of recording areas since the same data is duplicated. Further, although random access is possible, copying data takes a time in some degree and, as a result, editing also takes a long time.
Then, for example, in Japanese Patent Application Laid-Open Publication No. 9-163310 or Japanese Patent Application Laid-Open Publication No. 9-284690, the present applicant proposed a virtual file system in which a virtual file (or VFL) is prepared as a file of AV data after editing for avoiding a waste of a recording area and shortening an edit time.
That is, a normal file (file not the virtual file) is prepared by actually recording AV data constituting the file. The AV data constituting a file as an edit result are formed of AV data in the already recorded file. With respect to the file as an edit result, it is possible to reproduce the AV data just by identifying recording positions of the already recorded AV data constituting the file without actually recording the AV data.
Then, the virtual file system makes it possible to reproduce the file as the edit result (virtual file) without copying the actual AV data by preparing information about the recording position where the AV data constituting the file as the edit result are recorded. That is, the virtual file is reproduced by accessing the recording position on the basis of the information as to the recording position where the AV data as material data are recorded. Thus, the virtual file does not include the AV data constituting itself, but is reproduced by referring to the AV data of the normal file in which the AV data are actually recorded.
Now, as described above, since the virtual file does not include AV data constituting itself, if the file (reference destination file) including the AV data referred to by the virtual file is deleted, it becomes difficult to reproduce.
Then, for example, in the foregoing Japanese Patent Application Laid-Open Publication No. 9-163310 or Japanese Patent Application Laid-Open Publication No. 9-284690, the present applicant has proposed a method for, by using a deletable flag or a control flag, preventing the reference destination file from being inadvertently deleted.
That is, the method disclosed in Japanese Patent Application Laid-Open Publication No. 9-163310 or Japanese Patent Application Laid-Open Publication No. 9-284690 uses management information called a record entry to manage a recording area (record) where file data is continuously recorded on a recording medium. The record entry is provided with a deletable flag or control flag. The deletable flag or control flag is used for controlling whether to enable or disable deletion of data recorded in the recording area managed by the record entry. Consequently, the data of the reference destination file referred to by another file (virtual file) are not deleted even if an instruction is issued to delete the reference destination file.
When an instruction to delete a file is issued, however, the method of using such a deletable flag or control flag must search the deletable flag or control flag to determine availability of a virtual file which references the file data. Thus, when a normal file is to be deleted, it is necessary to search all record entries managing the recording area where the file data is recorded, which is troublesome.
The present invention has been made in consideration of the foregoing. It is therefore an object of the present invention to provide a file management device and method thereof, and an audio visual data recording/reproducing device and method thereof for easy file management.
The present invention is characterized in that a file management device for managing a file on a randomly accessible recording medium includes storage means and control means. The storage means stores file management information comprising file entry information and record entry information. The file entry information has an identification name for identifying the file and the number of references indicating the number of other files referencing the file. The record entry information specifies a recording area which continuously records the file on the recording medium. The control means controls the storage means so that the file management information is stored on the storage means. The control means also controls reproduction of a data file containing audio visual data based on the file entry information and the record entry information stored in the storage means.
The present invention is characterized in that a file management method for managing a file on a randomly accessible recording medium comprises a first step and a second step. The first step stores file management information on storage means. The file management information comprises file entry information and record entry information. The file entry information has an identification name for identifying the file and the number of references indicating the number of other files referencing the file. The record entry information specifies a recording area which continuously records the file on the recording medium. The second step reproduces a data file containing audio visual data recorded on the storage medium based on the file management information stored in the first step.
The present invention is characterized in that an audio visual data recording/reproducing device having a randomly accessible recording medium, recording/reproducing means, and a plurality of input/output means includes storage means and control means. The recording/reproducing means records and reproduces data containing audio visual data as a file on the recording medium. A plurality of input/output means outputs the externally input data accessed within a time slot allocated to the recording/reproducing means and inputs the data output from the recording/reproducing means. The storage means stores file management information comprising file entry information and record entry information. The file entry information has an identification name for identifying the file and the number of references indicating the number of other files referencing the file. The record entry information specifies a recording area which continuously records the file on the recording medium. The control means controls the storage means so that the file management information is stored on the storage means when the recording/reproducing means records the file on the recording medium. The control means also controls the recording/reproducing means based on the file management information so that the data is reproduced from the recording medium.
The present invention is characterized in that, with respect to recording/reproducing means for recording and reproducing data containing audio visual data as a file on a randomly accessible recording medium, an audio visual data recording/reproducing method for recording and reproducing the data comprises a first step and a second step. The first step stores file management information comprising file entry information and record entry information on a storage means when the recording/reproducing means stores the data on the recording medium. The second step allows the recording/reproducing means to reproduce a data stored on the recording medium based on the file management information stored by the storage means in the first step. Thereby, the audio visual data recording/reproducing method for recording and reproducing the data outputs the externally input data to the recording/reproducing means by accessing the recording/reproducing means within a time slot to which a plurality of input/output means is allocated and inputs the data output from the recording/reproducing means. The file entry information has an identification name for identifying the file and the number of references indicating the number of other files referencing the file. The record entry information specifies a recording area which continuously records the file on the recording medium.